Simplify type argument instantiation cache lookup by introducing an array

runtime/vm/stub_code_arm.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_ARM)
 
 #include "vm/assembler.h"
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
@@ skipping 1092 matching lines @@
   // The generated code is different if the class is parameterized.
   const bool is_cls_parameterized = cls.NumTypeArguments() > 0;
   ASSERT(!is_cls_parameterized ||
          (cls.type_arguments_field_offset() != Class::kNoTypeArguments));
   // kInlineInstanceSize is a constant used as a threshold for determining
   // when the object initialization should be done as a loop or as
   // straight line code.
   const int kInlineInstanceSize = 12;
   const intptr_t instance_size = cls.instance_size();
   ASSERT(instance_size > 0);
-  Label slow_case_with_type_arguments;
+  if (is_cls_parameterized) {
+    __ ldr(R1, Address(SP, 0));
+    // R1: instantiated type arguments.
+  }
   if (FLAG_inline_alloc && Heap::IsAllocatableInNewSpace(instance_size)) {
-    Label slow_case_reload_type_arguments;
-    if (is_cls_parameterized) {
-      __ ldr(R1, Address(SP, 0));
-      // R1: instantiated type arguments.
-    }
+    Label slow_case;
     // Allocate the object and update top to point to
     // next object start and initialize the allocated object.
     // R1: instantiated type arguments (if is_cls_parameterized).
     Heap* heap = Isolate::Current()->heap();
     __ LoadImmediate(R5, heap->TopAddress());
     __ ldr(R2, Address(R5, 0));
     __ AddImmediate(R3, R2, instance_size);
     // Check if the allocation fits into the remaining space.
     // R2: potential new object start.
     // R3: potential next object start.
     __ LoadImmediate(IP, heap->EndAddress());
     __ ldr(IP, Address(IP, 0));
     __ cmp(R3, ShifterOperand(IP));
     if (FLAG_use_slow_path) {
-      __ b(&slow_case_with_type_arguments);
+      __ b(&slow_case);
     } else {
-      __ b(&slow_case_with_type_arguments, CS);  // Unsigned higher or equal.
+      __ b(&slow_case, CS);  // Unsigned higher or equal.
     }
     __ str(R3, Address(R5, 0));
     __ UpdateAllocationStats(cls.id(), R5);
 
     // R2: new object start.
     // R3: next object start.
     // R1: new object type arguments (if is_cls_parameterized).
     // Set the tags.
     uword tags = 0;
     tags = RawObject::SizeTag::update(instance_size, tags);
@@ skipping 40 matching lines @@
       // R1: new object type arguments.
       // Set the type arguments in the new object.
       __ StoreToOffset(kWord, R1, R2, cls.type_arguments_field_offset());
     }
     // Done allocating and initializing the instance.
     // R2: new object still missing its heap tag.
     __ add(R0, R2, ShifterOperand(kHeapObjectTag));
     // R0: new object.
     __ Ret();
 
-    __ Bind(&slow_case_reload_type_arguments);
+    __ Bind(&slow_case);
   }
-  if (is_cls_parameterized) {
-    __ ldr(R1, Address(SP, 0));
-  }
-  __ Bind(&slow_case_with_type_arguments);
   // If is_cls_parameterized:
   // R1: new object type arguments.
   // Create a stub frame as we are pushing some objects on the stack before
   // calling into the runtime.
   __ EnterStubFrame(true);  // Uses pool pointer to pass cls to runtime.
   __ LoadImmediate(R2, reinterpret_cast<intptr_t>(Object::null()));
   __ Push(R2);  // Setup space on stack for return value.
   __ PushObject(cls);  // Push class of object to be allocated.
   if (is_cls_parameterized) {
     // Push type arguments.
@@ skipping 885 matching lines @@
   const Register right = R0;
   __ ldr(left, Address(SP, 1 * kWordSize));
   __ ldr(right, Address(SP, 0 * kWordSize));
   GenerateIdenticalWithNumberCheckStub(assembler, left, right, temp);
   __ Ret();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM